DERIVATIVES - Derivative Notionals (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Hedging instruments under ASC 815
Derivatives
Derivative notionals	$ 360,522	$ 374,383
Hedging instruments under ASC 815 | Interest rate contracts
Derivatives
Derivative notionals	272,320	277,003
Hedging instruments under ASC 815 | Interest rate swaps
Derivatives
Derivative notionals	272,320	277,003
Hedging instruments under ASC 815 | Interest rate futures and forwards
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Interest rate contract options | Written
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Interest rate contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Foreign exchange contracts
Derivatives
Derivative notionals	85,109	95,630
Hedging instruments under ASC 815 | Foreign exchange swaps
Derivatives
Derivative notionals	35,709	45,851
Hedging instruments under ASC 815 | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	49,400	49,779
Hedging instruments under ASC 815 | Foreign exchange contract options | Written
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contracts
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity futures and forwards
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contract options | Written
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Equity contract options | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contracts
Derivatives
Derivative notionals	3,093	1,750
Hedging instruments under ASC 815 | Commodity and other swaps
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other futures and forwards
Derivatives
Derivative notionals	3,093	1,750
Hedging instruments under ASC 815 | Commodity and other contracts | Written
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives | Written
Derivatives
Derivative notionals	0	0
Hedging instruments under ASC 815 | Credit derivatives | Purchased
Derivatives
Derivative notionals	0	0
Other derivative instruments, Trading derivatives
Derivatives
Derivative notionals	46,948,556	41,538,477
Other derivative instruments, Trading derivatives | Interest rate contracts
Derivatives
Derivative notionals	28,937,918	25,541,413
Other derivative instruments, Trading derivatives | Interest rate swaps
Derivatives
Derivative notionals	20,423,966	17,077,712
Other derivative instruments, Trading derivatives | Interest rate futures and forwards
Derivatives
Derivative notionals	3,490,013	3,022,127
Other derivative instruments, Trading derivatives | Interest rate contract options | Written
Derivatives
Derivative notionals	2,584,344	2,753,912
Other derivative instruments, Trading derivatives | Interest rate contract options | Purchased
Derivatives
Derivative notionals	2,439,595	2,687,662
Other derivative instruments, Trading derivatives | Foreign exchange contracts
Derivatives
Derivative notionals	15,284,615	13,229,648
Other derivative instruments, Trading derivatives | Foreign exchange swaps
Derivatives
Derivative notionals	8,298,674	7,943,054
Other derivative instruments, Trading derivatives | Foreign exchange futures, forwards and spot
Derivatives
Derivative notionals	4,822,868	3,737,063
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Written
Derivatives
Derivative notionals	1,082,059	778,397
Other derivative instruments, Trading derivatives | Foreign exchange contract options | Purchased
Derivatives
Derivative notionals	1,081,014	771,134
Other derivative instruments, Trading derivatives | Equity contracts
Derivatives
Derivative notionals	1,317,385	1,362,973
Other derivative instruments, Trading derivatives | Equity swaps
Derivatives
Derivative notionals	293,394	317,117
Other derivative instruments, Trading derivatives | Equity futures and forwards
Derivatives
Derivative notionals	78,102	72,592
Other derivative instruments, Trading derivatives | Equity contract options | Written
Derivatives
Derivative notionals	539,076	544,315
Other derivative instruments, Trading derivatives | Equity contract options | Purchased
Derivatives
Derivative notionals	406,813	428,949
Other derivative instruments, Trading derivatives | Commodity and other contracts
Derivatives
Derivative notionals	362,526	340,117
Other derivative instruments, Trading derivatives | Commodity and other swaps
Derivatives
Derivative notionals	77,801	82,009
Other derivative instruments, Trading derivatives | Commodity and other futures and forwards
Derivatives
Derivative notionals	167,194	161,811
Other derivative instruments, Trading derivatives | Commodity and other contracts | Written
Derivatives
Derivative notionals	59,172	49,555
Other derivative instruments, Trading derivatives | Commodity and other contracts | Purchased
Derivatives
Derivative notionals	58,359	46,742
Other derivative instruments, Trading derivatives | Credit derivatives
Derivatives
Derivative notionals	1,046,112	1,064,326
Other derivative instruments, Trading derivatives | Credit derivatives | Written
Derivatives
Derivative notionals	483,472	496,699
Other derivative instruments, Trading derivatives | Credit derivatives | Purchased
Derivatives
Derivative notionals	$ 562,640	$ 567,627